Issues with typescript definitions

[cynodia]

If using config option "followRedirects", the param passed in the promise is an array of NettimeResponses. This causes TS-validation to fail as this is not part of the definition in nettime.d.ts
As far as I can see the return value should be
Promise<NettimeResponse | NettimeResponse []>

[cynodia]

Also it seems the helper-function definitions are not correctly defines. Eg.
getDuration (start: number, end: number): number
getMilliseconds (timings: number[]): number

should probably be:
getDuration (start: number[], end: number[]) : [ number, number]
getMilliseconds ([seconds, nanoseconds] : [number, number])

(....and now I see there was already a pull-request for this)